Aliso: A Journal of Systematic and Evolutionary Botany

Volume 4 | Issue 3 Article 10

1960 Investigations of Meiotic Chromosomes of Six Genera in the David P. Gregory

William M. Klein

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Recommended Citation Gregory, David P. and Klein, William M. (1960) "Investigations of Meiotic Chromosomes of Six Genera in the Onagraceae," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 4: Iss. 3, Article 10. Available at: http://scholarship.claremont.edu/aliso/vol4/iss3/10 ALISO

Vm. 4, No.3, pp. 505-521 APRIL 29, 1960

INVESTIGATIONS OF MEIOTIC CHROMOSOMES OF SIX GENERA IN THE ONAGRACEAE

DAVID P. GREGORY AND WILLIAM M. KLEIN INTRODUCTION Numerous cytological studies have been made in the Onagraceae during the last few years (see Cleland, 1950; Lewis and Lewis, 195 5, and Lewis et al., 1958). Some of these studies have provided valuable data in connection with detailed cytogenetic and taxonomic investigations. Other scattered observations have been reported in an effort to gain a more complete knowledge of the basic numbers in the family and of such phenomena as trans­ location heterozygosity, polyploidy and occurrence of diminutive chromosomes and super­ numeraries. The observations reported here are the results of a two year investigation, some from a detailed study in one group ( subgenus Anogra), the others scattered through species of several genera to survey the family further. All of the observations have been made using pollen mother cells so that the degree of translocation heterozygosity could be determined. Most of the material used was collected from wild populations, but some was obtained from grown at the Rancho Santa Ana Botanic Garden. Seed was gathered by the authors or supplied by botanists or Botanic Gar­ dens as indicated in the table. The determinations have either been made by Dr. Philip A. Munz or are based on his revision of the group concerned. Voucher specimens have been deposited in the herbarium of the Rancho Santa Ana Botanic Garden. The technique used for the meiotic squashes is that given by Lewis (Lewis and Lewis, 1955) with the use of Hoyer's medium to make the slides permanent (Beeks, 1955). Buds, fixed in 1:3 glacial acetic acid and ethyl alcohol and stored in the refrigerator, were hydro­ lysed in a mixture of equal parts of concentrated HCl and 95 per cent ethyl alcohol for a period of from ten to twenty minutes depending upon the material. The anthers were stained with aceta- or propriono-carmine. A phase contrast microscope was used for in­ terpretation of all slides, and drawings were made with the aid of a camera lucida at the magnifications indicated on the plates. Chromosomes were sometimes moved in the draw­ ings where they overlapped and could cause confusion, but not in cases of questionable interpretation. The degree of translocation heterozygosity is reported wherever it could be analyzed. DISCUSSION . The chromosome number of thirteen of the currently recognized eighteen species has now been counted at least once, all having the basic number of seven. Most of the species are diploids, but polyploids have been found in three species. Translocation hetero­ zygosity is present in the diploids as indicated by rings of from four to twelve chromosomes. The two species with actinomorphic flowers, G. mutabilis and G. macrocarpa, are diploids with a small ring in one of G. macrocarpa. The group of related species, G. gracilis, G. nealleyi, G. suffulta and G. brachycarpa, consists of diploids with a maximum association of four chromosomes in a ring in addition to the bivalents. Gaura villosa and G. sinuata have more translocations in some plants with a maximum association in each

1The work on which this paper is based was financed in part by Grant 4316 from the National Science Foundation, to which grateful acknowledgment is made. [505] 506 ALISO [VoL. 4, No. 1

TABLE 1. NUMBER OF CHROMOSOMES AND MEIOTIC AssOCIATION Gametic Meiotic Locality and Investi- number associations' collector gator ----- GaUI·a: Gauridium mutabilis Cav. 7 7II El Sal to, Durango, Mexico G (RSABG). f. H. Maysilles 7792. Gaura: Eugaura brachycarfJa Small. 7 511+r4 5 mi. s. of Seguin, G Guadalupe Co., Texas. Munz and Gregory 23442. coccinea Nutt. var. 14 ( 6II + 1ch4 6.8 mi. w. of Crystal, Clark G coccinea. +3s +3r4) 2 Co., Nevada. Gregory 33. 14 ( 6II+4r4) 30 mi. se. of Carp, Clark Co., G +3s Nevada. Gregory 50. 14 ( 3II + 1a6 1 mi. n. of Jean, Clark Co., G +2s +4a4) Nevada. Gregory 56. 21 30 mi. s. of Mason, Gillespie G Co., Texas. Munz and Gregory 23434. coccinea var. glabra 14 1 mi. s. of The Forks, G (Lehm.) Torr. and Highway 287, Larimer Co., Gray. Colorado. H. and M. Lewis 1183. coccinea var. 14 49 mi. e. of Sanderson, G epilobioides +1s Terrell Co., Texas. Gregory (H. B. K.) Munz. 277. 21 11 mi. s. of Toyahvale, Jeff G Davis Co., Texas. Munz and Gregory 23377. 21 29 mi. ne. of Mexico City, G Mexico, Mexico. Ted Anderson 1083. coccmea var. 21 Globe, Gila Co., Arizona. G arizonica Munz. Munz and Gregory 23322. gracilis Woot. and 7 5II+r4 6 mi. e. of Superior, Pima Co., G Standi. var. Arizona. Munz and Gregory gracilis. 23321. lindheimeri Engelm. 7 1II+2r6 10 mi. e. of Beaumont, Orange G and Gray. Co., Texas. Munz and Gregory 23460. macrocarpa Rothrock. 7 7II 13 mi. n. of Fort Davis, Jeff G Davis Co., Texas. Munz and Gregory 23380. 7 511+r4 Same G nealleyi Coulter. 7 7II 27 mi. e. of Mayhill, Chaves G Co., New Mexico. Munz and Gregory 23345. 7 7II 5 mi. w. of Alpine, Brewster G Co., Texas. Munz and Gregory 23393.

1 In this table r=ring, ch=chain, II=bivalent, !=univalent, a=association, s=supernumerary chromo­ some, RSABG=grown at the Rancho Santa Ana Botanic Garden from seed from the source indicated. If more than one plant of a collection was examined the number is given in parentheses. Meiotic asso­ ciations that could not be determined exactly are also included in parentheses. 2The associations of chromosomes in polyploid species may be due either to translocation hetero­ zygosity or to multivalent pairing, but they are indicated as in the diploids. APRIL, 1960] ONAGRACEAE 507

Gametic Meiotic Locality and lnvesti- number aSJociations1 collector gator

odorata Sesse ex. 14 (?II+ 1a6 7 mi. s. of. Fr~dericksburg, G Lag. or8+3a4) Gillespie Co., Texas. Munz a.·zd Gregory 23436. 14 ( 5II + 1a6+ 20 mi. n. of Beeville, Bee Co., G 3a4) Texas. Munz and Gregory 23445. /Jarvi flora var. 7 7II 14 mi. e. of Alamogordo, G lachnocarpa Otero Co., New Mexico. Munz Weatherby. and Gregory 23341. sinuata Nutt. ex 7 7II 4.5 mi. se. of Brady, G Seringe. McCulloch Co., Texas. Munz and Gregory 23430. 7 5Il+r4 2.5 mi. w. of Eden, Concho G Co., Texas. Munz and Gregory 23424. 7 2II+r4+r6 3 mi. n. of Fort Davis, Jeff G Davis Co., Texas. Munz and Gregory 23383. 14 4II+ch4+ 7 mi. s. of Fredericksburg, G 2r4+r8 Gillespie Co., Texas. Munz and Gre,;ory 23437. sulfulta Engelm. ex 7 3.5 mi. se. of Brady, G Gray. var. su/fulta. McCulloch Co., Texas. Munz and Gregory 23427. sulfulta var. 7 711 5 mi. w. of Sanderson, G terrellensis Munz. Terrell Co., Texas. Munz and Gregory 23403. villo.ra var. 7 7II Ward Co., Texas (RSABG). G menicola Munz. Turner and Warnock 69. 7 5II+r4 1 mi. e. of Monahans, Ward G Co., Texas. lHunz and Gregory 23408. villosa Torrey var. 7 2II+r4+r6 5 mi. e. of Midland, Midland G villosa. Co., Texas. Munz and Gregory 23415. Jussiaea: Myrtocarpus caparosa Camb. 16 161I (RSABG). USDA 18946. G decurrens (Walt.) 8 8II Just w. of Caryville, G D.C. Washington Co., Florida ( RSABG). Godfrey and Kral 55164. erecta L. 8 8II Nw. of Toxahatchee, Palm G Beach Co., Florida ( RSABG). Kra/5702. 8 8II 10 mi. se. of Naples, Collier G Co., Florida. Munz and Gregory 23474. lon,;ifolia D. C. var. 8 8II (RSABG). USDA 18756. G longifolia. peruviana L. 48 48II 1.5 mi. s. of Fort Meade, G Polk Co., Florida. Munz and Gregory 23470. sericea var. genuina 16 16II (RSABG). USDA 18763. G Munz. ] uSJiaea: Macrocarpon su/fruticosa var. 16 16II 10 mi. se. of Naples, Collier G ligustrifolia Co., Florida (RSABG). Munz (H. B. K.) Griseb. and Gregory 23475. 508 ALISO [VOL. 4, ~0. 3

Gametic Meiotic Locality and lnvesti- number associations1 collector gator

fussiaea: Eujussiaea leptocarpa Nutt. 16 1611 Boggy Bayou, Freeport, Walton G Co., Florida (RSABG). Godfrey 57651. repens var. pep/aides 8 811 Cultivated in the pond at the G (H. K.B.) Griseb. Rancho Santa Ana Botanic Garden. repens var. glabre.rcens 8 S.S mi. se. of Presidio, G 0. Kuntze. Presidio Co., Texas. Gregory 224. Lopezia coronata Andrews 10 lOll (RSABG), seed from the Botanic G Garden at Copenhagen. Munz and Gregory 23316. 10 lOll (RSABG), seed from Hortus G Bergianus at Stockholm. Munz and Gregory 23318. mexicana Jacq. 10 lOll (RSABG), seed from the Botanic G Garden at Lisbon. Munz and Gregory 23319. Ludwiy,ia: Dantia palustris var. 8 811 10 mi. w. of Hot Springs, G americana (D. C.) Garland Co., Arkansas. Munz Fern. and Griscom. and Gregory 23502. palu.rtris var. nana 8 811 12 mi. w. of Beaumont, G Fern. and Griscom. Jefferson Co., Texas. Munz and Gregory 23459. natans Ell. var. 24 24II 3 7 mi. se. of Perry, Dixie G natans. Co., Florida. Munz and Gregory 23467. Ludwigia: Ludwigiantha arcuata Walt. 16 16II 2 mi. s. of Oakland, Orange G Co., Florida (RSABG). Godfrey 57332. Ludwigia: Ludwigiaria Garland Co., Arkansas (RSABG). G alternifolia var. 8 8II Demaree 40523. pube.rcen.r Palmer and Steyermark. maritima Harper. 8II 14 mi. s. of Oakland, Orange G Co., Florida (RSABG). Godfrey 57354. Ludwigia: Microcarpium curtissii Chapman. 24 24II 10 mi. se. of Naples, Collier G Co., Florida. Munz and Gregory 23476. glandulosa Walt. var. 16 16II Leon Co., Florida ( RSABG). Seed G glandulosa. collected by Godfrey. linifolia Poir. 8 8II 3 mi. e. of Ocean Springs, G Jackson Co., Mississippi (RSABG). Demaree 37879. simpsonii Chapman. 24 2411 6 mi. s. of Stuart, Martin G Co., Florida (RSABG). Munz and Gregory 23481. sphaerocarpa Elliot 16 16II (RSABG). Monoson 55. G var. sphaerocarpa. Oenothera: Anogra californica Wats. var. 7 7II S mi. s. Oasis, lnyo Co., K californica. . Klein 339. (Great Basin) APRIL, 1960] ONAGRACEAE 509

Gametic Meiotic Locality and lnvesti- number associationsl collector gator

7 7II Cedar Canyon, San Bernardino K Co., California. Klein 926. 7 7II 0.5 mi. ne. of Leeds, K Washington Co., Utah. Klein 1049. 7 5II+r4 Same. K 7 7II Pine Valley, Washington Co., K Utah. Klein 1052. 7 511+r4 Same. Klein 1054. K 7 711 23 mi. w. of Beaver, Beaver K Co., Utah. Klein 1060. 7 7II(2) 8.5 mi. w. of Milford, Beaver K Co., Utah. Klein 1064. 7 511+r4 2 mi. w. of Austin, Lander Co., K Nevada. Klein 1069. californica Wats. var. 14 4II+2r4+ Morongo Valley, San Bernardino K californica. 2ch4+1ch3+ Co., California. Klein 867. (Coastal Ranges of 1I ) 14 23 mi. n. of Castaic, Los Angeles K Co., California. Klein 475. deltoides Torr. and 7 7II 3.6 mi. s. of Kane Springs, K Frem. var. deltoides. Imperial Co., California. Klein 61. 7 711 4. 5 mi. n. of Ripley, Riverside K Co., California. Klein 147. 7 711 10 mi. e. of Yuma on Highway K 95, Yuma Co., Arizona. Munz, Gregory, and Klein 22965. 7 7II(3) Bermuda Dunes, Riverside Co., K California. Klein 797, 802, 805. 7 511+r4 Bermuda Dunes, Riverside Co., K California. Klein 800. 7 7II(2) 3 mi. nw. of Bouse, Yuma Co., K Arizona. Klein 961, 962. 7 5II+r4 2.5 mi. nw. of Bouse, Yuma Co., K Arizona. Klein 960. 7 Highway 99, 20 mi. s. of the K Riverside-Imperial Co. line, Imperial Co., California. Klein 54. deltoides var. 7 711 Boulder City, Clark Co., K ambigua Munz. Nevada. Munz, Gregory, and Klein 22988. deltoides var. 7 3II+r4+ 18 mi. nw. of Hope, Yuma Co., K arizonica Munz. ch4 Arizona. Klein 955. 7 7II Same. V. E. and A. Grant K 10074. deltoides var. 7 711 Highway 80, 5 mi. e. of K cineracea Munz. Holtville, Imperial Co., California. Klein 75. 7 7II 3.5 mi. nw. of Indio City Limits, K Riverside Co., California. Munz, Gregory, and Klein 22962. deltoides var. 7 711 Highway 140, 20 mi. w. of K cognata (Jeps.) Merced, Merced Co., California. Munz. Kein 443. deltoides subsp. 7 7II Eureka Valley, lnyo Co., K eurekensis Munz California. Klein 383. and Roos. 510 ALISO [VoL. 4, No. 3

Gametic Meiotic Locality and Investi- number associations! collector gator

deltoides var. 7 5II+r4 Antioch, Contra Costa Co., K howellii Munz. California. Klein 440. deltoides var. pi peri 7 7II 16 mi. ne. of Carson City, K Munz. Lyon Co., Nevada. Klein 425. 7 5II+r4 Same. Klein 426. K 7 7II (5) 5 mi. e. of Carson City, Lyon Co., K Nevada. Klein 1080, 1086, 1085, 1082, and 1079. 7 5II+r4 Same. Klein 1081. K enf!.elmanni (Small) 7 5II+r4 3 mi. w. of Big Spring, K Munz. Howard Co., Texas. Gregory 294. nuttallii Sweet. 7 5II+r4 Green Mountain Reservoir, K Summit Co., Colorado. H. and M. Lewis 1172. 14 4II+2r4+ 12 mi. n. of Livermore, K ch4+ch8 Larimer Co., Colorado. Klein 1136. 14 (3II+4r4+ 12 mi. s. of Laramie, Albany K ch6) Co., Wyoming. H. and M. Lewis 1185. 14 19 mi. n. of Laramie, Albany K Co., Wyoming. Klein 1138. pall ida Lind!. 7 2II+r6+r4 Highway 93, 6.5 mi. s. of the K Idaho-Nevada state line, Elko Co., Nevada. Klein 1153. 7 3II+rs 11 mi. nw. of the south K entrance to Zion National Park, Washington Co., Utah. Klein 1094. runcinata (Engelm.) 7 7II 14.6 mi. ne. of Horse Springs, K Munz. var. runcinata. Catron Co., New Mexico. Gregory 323. runcinata var. 7 5II+r4 White Sands National Monument, K gypsophila (Eastwood) Otero Co., New Mexico. Gregory Munz. 309-313. trichocalyx Nutt. 7 5II+r4 Highway 6 and 50, 10 mi. e. of K Wellington, Carbon Co., Utah. Klein 1099. Oenothera: Calylophis serrulata var. 7 5II+r4 5 mi. n. of Stockdale, Wilson G pinifolia Engelm. Co., Texas. Munz and Gregory 23443. 7 3II+r8 6 mi. sw. of White City, Eddy G Co., New Mexico. Munz and Gregory 23359. serrulata var. 7 2II+r4+r6 9 mi. se. of Brady, McCulloch G drummondii f. (lava Co., Texas. Munz and Gregory Munz. 23431. Oenothera: Eulobus crassifolia Greene. 7 10 mi. s. of San Quintin, G Baja California, Mexico. Klein 13. Oenothera: Hartmannia deserticola ( Loesener) 7 7II Near Rio Frio, Mexico City- G Munz. Puebla Highway, Mexico, Mexico (RSABG). Straw and Gregory 1120. 7 Lagunas de Zempoala, Morelos, G Mexico ( RSABG). Straw and Gregory 1068. APRIL, 1960] ONAGRACEAE 511

Gametic Meiotic Locality and Investi- number associations1 collector gator

speciosa Nutt. var. 7 7II 10 mi. e. of Boerne, Kendall G speciosa. Co., Texas. Munz and Gregory 23439. 7 5II+r4 5 mi. w. of Garden City, G Glasscock Co., Texas. Munz and Gregory 23418. speciosa var. childsii 14 15 mi. w. of Beaumont, Jefferson G (Bailey) Munz. Co., Texas. Munz and Gregory 23456. 21 7II+ch6+ 13 mi. sw. of West Columbia, G 2ch4+r6+2r4 Matagorda Co., Texas. Munz and Gregory 23452. Oenothera: Kneifiia linifolia N utt. var. 7 7II 5 mi. w. of Mt. Ida, Montgomery G linifolia. Co., Arkansas (RSABG). Munz and Gregory 23503. spachiana Torr. and 7 7II Kingston, Marshall Co., G Gray. Oklahoma (RSABG). Waterfall 11448. fruticosa var. vera 14 10 mi. n. of Charlotte, G f. angustifolia Levi. l\1ecklenburg Co., N. Carolina. Mtmz and Gref!.ory 23497. tetragona var. 14 13 mi. w. of Savannah, Hardin G brevisti pat a Co., Tennessee. Munz and Gref!.ory (Pennell) Munz. 23500. tetraJ!.ona Roth. var. 14 N. of Saluda, Saluda Co., G tetragona. S. Carolina. Munz and Gregory 23496. 21 5II+ch6+ 3 mi. n. of Hardeeville, G ch4+r6+4r4 Jasper Co., S. Carolina. Munz and Gref!.ory 23491. Oenothera: lavauxia taraxacoides (Woot. 7 2II+r4+r6 4 mi. e. of El Saito, Durango, G and Standi.) Munz. Mexico (RSABG). Waterfall 13711. Oenothera: Megapterium brachycarpa var. 7 7II 18.3 mi. s. of Toyahvale, Jeff G wrightii (A. Gray) Davis Co., Texas. Gregory 170. Leveille.

7 5II+ch4 1 mi. e. of Emery Pass, Mimbres G Mtns., Sierra Co., New Mexico. Munz and Gregory 23331. 7 27 mi. e. of Mayhill, Chaves G Co., New Mexico. Munz and Gref!.ory 23343. Oenothera: Pachylophis caespitosa var. 7 srr+ch4 9.8 mi. n. of Coleville, Mono G marginata (Nutt.) Co., California. Klein 416. Munz. xylocarpa Coville. 7 4 mi. s. of Crestview, Mono G Co., California. Klein 401. Oenothera: Raimannia albicaulis Pursh. 7 7II 1.7 mi. w. of Mule Creek, G Grant Co., New Mexico. Munz and Gregory 23326. 7 5II+r4 1.7 mi. w. of Mule Creek, G Grant Co., New Mexico. Munz and Gregory 23325. 512 ALISO [VoL. 4, No. 3

Gametic Meiotic Locality and Investi- number associationsl collector gator

coronopifolia T. and G. 7 5II+r4 Twin Lakes, Lake Co., Colorado. K H. and M. Lewis 1168. 14 2II+chs+ 6 mi. e. of Flagstaff, G 4r4 Coconino Co., Arizona. Munz and Gregory 23523. drummodii Hook. var. 7 4II+r6 8 mi. ne. of Tampico, G drummondii. Tamaulipas, Mexico (RSABG). U. T. W.4terfall14644. 7 4II+r6 E. of Aransas Pass, San G Patricio Co., Texas. Munz and Gregory 23450. 7 2II+r4+r6 Same. G humifusa Nutt. 7 ( r12 or Lake Park, Palm Beach Co., G 14) Florida. Munz and Gregory 23480. laciniata Hill. var. 7 10 mi. n. of Brunswick, Glynn G laciniata. Co., Georgia. Munz and Gregory 23489. 7 Pass Christian, Harrison Co., G Mississippi. Munz and Gregory 23461. laciniata var. 7 7II 3 mi. se. of Midland, Midland G grandiflora (Wats.) Co., Texas. Munz and Gregory Robinson. 23411. laciniata var. 7 r14 Off the old highway between G pubescens (Willd.) Mexico City and Cuernavaca, Munz. Morelos, Mexico ( RSABG). Straw and Gregory 1075. rhombipetala Nutt. ex 7 7II 5 mi. w. of Elk City, Beckham G T. and G. Co., Oklahoma. Munz and Gregory 23511. 7 3II+2r4 Waddell Ranch, Winkler Co., G Texas. (RSABG). H. Nessmith 124. Oenothera: Salpingia tubicula A. Gray. 7 7II 5 mi. n. of Marfa, Presidio G Co., Texas.Munz and Gregory 23389. 7 5II+r4 4 mi. w. of Hope, Eddy Co., G New Mexico. Munz and Gregory 23350. 7 5II+r4 Carlsbad, Eddy Co., New Mexico. G Munz and Gregory 23353. hartwegii Benth. var. 7 5II+r4 Santa Rosa, Guadalupe Co., New G hartwegii. Mexico. Munz and Gregory 23516. 7 2II+r4+r6 6 mi. sw. of White City, Eddy G Co., New Mexico. Munz and Gregory 23357. hartwegii var. fendleri 7 5II+r4 6 mi. se. of Elk, Chaves Co., G Gray. New Mexico. Munz and Gregory 23346. hartwegii var. 7 3II+2r4 White Sands National Monument, G filifolia (Eastw.) Otero Co., New Mexico. Munz Munz. and Gregory 23335. greggii var. lam pas ana 7 5II+r4 2.5 mi. w. of Eden, Concho Co., G (Buckley) Munz. Texas. Munz and Gregory 23425. APRIL, 1960] ONAGRACEAE 513

Gametic Meiotic Locality and Investi- number associations! collector gator

7 4II+ch6 29 mi. sw. of White City, New G Mexico, Culberson Co., Texas. Munz and Gregory 23364. 7 2II+r4+r6 4 mi. s. of Alpine, Brewster G Co., Texas. Munz and Gregory 23395. Oenothera: Sphaerostigma dentata var. 7 7II Jawbone Canyon, Kern Co., G johnstonii Munz. California. Munz and Gregory 23310. 7 7II 10 mi. n. of Red Rock Canyon, G Kern Co., California. Munz and Gregory 23313. Stenosiphon linifolium (Nutt.) 7 3II+2r4 22 mi. w. of El Reno, Caddo G Britton. Co., Oklahoma. Munz and Gregory 23507. species of one ring of four plus one of six. Bhaduri ( 1942) has reported a ring of twelve in G. biennis which is the largest ring known in the genus. He also reports (1941, 1942) a ring of six in one plant and two rings of four in another in G. lindheimeri, whereas the collection reported here has two rings of six. With more intensive sampling, complex trans­ location heterozygosity may prove to be extensive among this group of eastern species, four of which have not been studied cytologically. Three collections of G. sinuata were diploid and a fourth strain of G. sinuata which was growing with G. odorata was tetraploid. Lewis et al. (1958) have also reported a tetraploid count for this species. Lewis recorded four associations of four chromosomes in the tetra­ ploid, and in the tetraploid counted here there were three associations of four and one of eight. Gaura odorata is probably a tetraploid species (the collection reported as diploid in Lewis et al., 1958, is actually G. suffulta). There were seven associations of four in the plant counted by Lewis and he suggested it to be an autoploid. The two collections given in this paper could not be analyzed exactly, but one had one association of six or eight and at least two of four chromosomes. The other had one of six and probably three of four chromo­ somes. Though not as strong an indication of autoploidy as the previous one, these con­ figurations would not be inconsistent with such an interpretation. Gaura coccinea includes plants with gametic numbers of 7 (Lewis et al., 1958), 14 and 21. There is much morpho­ logical variation in both the tetraploid and the hexaploid and these levels are not com­ pletely separated geographically, as one of the tetraploid plants is from west Texas, where all three levels occur. No morphological characteristics correlating with and differentiating the three chromosomal levels have been found as yet. The exact extent of chromosome association has been hard to determine in the preparations of G. coccinea polyploids. Gaura coccinea is a widespread and highly variable species and as presently constituted probably contains more than one species. Plants with one, two or three small supernumerary chromo­ somes were found in four of the tetraploid collections. In one, with two supernumeraries, the chromosomes seemed to form a diminutive pair at metaphase I. Jussiaea. The nine species of the genus for which chromosome counts are reported here all have the basic number eight, and polyploidy seems common and is probably well ad­ vanced as indicated by the dodecaploid species, J. peruviana. Of the nine species counted four were diploid, four tetraploid and one dodecaploid. There are no hexaploids known in Jussiaea although three have been found in Ludwigia. There are chromosomal size differ­ ences between species of Jussiaea as well as Ludwigia, but these do not seem to be correlated 514 ALISO [VoL. 4, No. 3 with polyploid level. There are roughly two size categories and both are found in each genus. Ludwigia. As in Jussiaea the basic number is eight, evidence supporting the recent sug­ gestion (Brenan, 1953; Hara, 1953) that the two genera be placed in one. Polyploidy is again evident, for of the ten species counted four were diploid, three tetraploid and three hexaploid. There was no indication of translocation heterozygosity in either Ludwigia or Jussiaea. Lopezia. The two counts of ten pairs of chromosomes for L. coronata, when considered with the two identical counts for L. mexicana (the specimen reported in Lewis et al., 1958, as L. lineata is actually L. mexicana), suggest that Tackholm' s ( 1914) report of eleven pairs for L. coronata might have been in error. Oenothera: Anogra. In this subgenus chromosome studies at meiosis have been made for all but two of the nine species treated in the revision by Munz ( 1931). Five of these species are diploid, and for two others, Oe. californica and Oe. nuttallii, both diploid and tetraploid forms are known. The tetraploids of Oe. californica which have been reported thus far (Lewis et al., 1958; Snow, 1959) were located in the coastal ranges of southern California. The diploid material which has been attributed to this same species centers in the Great Basin region. The maxi­ mum associations in the tetraploids reported here are four associations of four and a chain of three. Lewis et al. (1958) reported a maximum association of two rings or chains of eight and two of four chromosomes. Plants from the Great Basin region were commonly found to possess small rings, and individuals which were structurally homozygous, or heterozygous for a single translocation, were found in the same colony. The diploid material of Oe. nuttallii was obtained from a single collection made in the Rocky Mountains of Colorado near the Green Mountain Dam. It was found to be hetero­ zygous for a single translocation. The tetraploid material was from the plains and foothills just east of the Rocky Mountains near Laramie, Wyoming. The maximum meiotic associa­ tion in the tetraploid was a chain of eight and three associations of four. All of the entities presently included in the Oe. deltoides species complex have been counted at least once. Most of the material is structurally homozygous but where quite a number of individuals were examined it has usually been possible to find a few plants which are heterozygous for at least one translocation. The highest number of translocations en­ countered was in the variety arizonica which had two associations of four. The other species of the subgenus so far observed are either seven paired or heterozygous for a single translocation, with one notable exception, Oe. pallida. In material from Zion Canyon National Park, an area in which three of the species in the subgenus are closely associated (Oe. californica [Great Basin], Oe. runcinata and Oe. pallida), chromosome associations of intermediate size have been found. Other material which has been collected from this region has been found to be somewhat intermediate morphologically and has been variously assigned to the three species mentioned above and also to a fourth, Oe. tri­ chocalyx. A collection of Oe. pallida from northeastern Nevada had a ring of six and one of four. In summary it can be said that this subgenus consists primarily of diploid individuals

PLATE 1. Camera Iucida drawings of chromosomes during meiosis in species of Gaura and Stenosiphon. Figures 1, 2, 4, 6, 8, and 11, diakinesis; figures 3, 5, 7, 9, and 10, first metaphase. 1. Gaura linde­ heimeri, one pair and two rings of six. 2. Gaura brachycarpa, five pairs and a ring of four. 3. Gaura parviflora, seven pairs. 4. Gaura gracilis, five pairs and a ring of four. 5. Gaura suffulta var. terre/len­ sis, seven pairs. 6. Gaur a villosa var. arenicola, five pairs and a ring of four. 7. Gaur a macrocarpa, seven pairs. 8. Gaura sinuata, two pairs, a ring of six, and a ring of four. 9. Gaura coccinea var. epilo­ bioides, 42 chromosomes, associations not determinable. 10. Gaura coccinea, 28 chromosomes, associa­ tions not completely determinable, plus three supernumerary chromosomes. 11. Stenosiphon linifolium, three pairs and two rings of four. All drawings X 1600. 515 ONAGRACEAE APRIL, 1960]

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PLATE 2. Camera Iucida drawings of chromosomes during meiosis in species of Ludwigia and Jussiaea. Figures' 1 and 2, first metaphase; ligures 3-5, diakinesis. 1. Ludwigia maritima, eight pairs. 2. J ussiaea repens var. pep/aides, eight pairs. 3. Jussiaea peruviana, 48 pairs. 4. fussiaea leptocarpa, sixteen pairs. 5. Ludwigia natans, 24 pairs. Figures 1, 2, 4, and 5, X 1600; figure 3, X 1350. APRIL, 1960] ONAGRACEAE 517

2.

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5. 6.

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7. 9. PLATE 3. Camera Iucida" drawings of chromosomes during meiosis in species of Oenothera subgenus Anogra. Figure 1, first metaphase; figures 2-9, diakinesis. L Oeonthera californica (Great Basin), seven pairs. 2. Oenothera californica (Coastal Ranges), four pairs, two chains of four, two rings of four, chain of three and one univalent. 3. Oenothera deltoides var. deltoides, five pairs and a ring of four. 4. Oenothera engelmanni, five pairs and a ring of four. 5. Oenothera nuttallii, five pairs and a ring of four. 6. Oenothera nuttallii, four pairs, two rings of four, a chain of four, and a chain of eight. 7. Oenothera pal/ida, three pairs and a ring of eight. 8. Oenothera runcinata, seven pairs. 9. Oenothera trichocalyx, five pairs and a ring of four. All drawings X 1350. 518 ALISO [VoL. 4, No. 3 which are structurally homozygous but with single translocations occasionally found in the colonies. The only exception to this is Oe. pallida in which associations of intermediate size occur. Two of the species have tetraploid representatives which because of their chromo­ some associations at meiosis (see Hecht, 1942; Lewis eta!., 1958, and Snow, 1959) and also because of their morphological similarity to a diploid strongly suggest that they are autotetraploids. Oenothera: Calylophis. The meiotic investigations given here indicate that Oe. serrulata is a diploid with rings of intermediate size. This is consistent with the reports of Lewis eta!. (1958) and Linder and Brun (1957). Oenothera: Hartmannia. Reports for this subgenus so far include two species with com­ plete rings of fourteen and one species with polyploidy (Hagen, 1950). One of the species reported here, Oe. deserticola, was structurally homo.::ygous. Three gametic numbers, 7, 14 and 21, have now been reported for Oe. speciosa, including the hexaploid given in this paper. From the investigations to date, the typical variety is composed of diploids having from seven pairs to two rings of four and three pairs. The variety childsii has been studied by Hagen (1950) who reports a 2n number ranging from 28 to 35 chromosomes, appar­ ently in different individuals. The two plants of this variety reported here are tetraploid and hexaploid. Because there is a hexaploid in the species, geographically very close to the tetraploid, Hagen's plant with 35 chromosomes was probably a pentaploid hybrid between the tetraploid and hexaploid and the plants with numbers between 20 and 35 may have been progeny of this hybrid. Oenothera: Kneiffia. Two diploids are reported here, one, Oe. spachiana, with small chromosomes compared to the other Oenotheras studied (see plate 4). Both Oe. fruticosa and Oe. tetragona are polyploid; the first including a tetraploid and an octoploid reported by Hecht ( 1942), and the second including a tetraploid and a hexaploid. Hagen ( 1950) studied a tetraploid collection in which he found configurations of from 14 pairs to seven rings of four, and he suggests that " ... this strain was derived from a structurally homo­ zygous diploid." The tetraploids given in this paper could not be analyzed, but the hexa­ ploid showed two associations of six plus five associations of four. Oenothera: Lavauxia. This subgenus has at least one species with a ring of fourteen and four with very little translocation heterozygosity (Hagen, 1950). The species reported here is intermediate in this respect with a ring of four and a ring of six. Oenothera: Raimannia. A detailed study of fourteen of the nineteen species of this sub­ genus was made by Hecht (1950). The observations included here consider two additional species and a few of the species which he studied. In one species not investigated by Hecht ( 1950), Oe. coronopifolia, there are both diploid and tetraploid representatives. The tetra­ ploid plant had a chain of eight chromosomes, four rings of four and two pairs. Another species not reported by Hecht (1950) is Oe. humifusa. In the plant studied here it was not possible to get an exact analysis but there was one large ring, probably of twelve chromosomes, but possibly of fourteen. This would be typical of many of the other species reported by Hecht. The counts given here for Oe. laciniata also corroborate Hecht's analysis of this group,

PLATE 4. Camera Iucida drawings of chromosomes during meiosis in species of Oenothera. Figures 1-8, 12, and 13, first metaphase; figures 9-11, diakinesis. 1. Oenothera serrulata var. pinifolia, five pairs and a ring of four. 2. Oenothera spachiana, seven pairs. 3. Oenothera speciosa, seven pairs. 4. Oeno­ thera brachycarpa var. wrightii, seven pairs. 5. Oenothera taraxacides, two pairs, a ring of four, and a ring of six. 6. Oenothera caespitosa var. marginata, five pairs and a chain of four. 7. Oenothera albi­ caulis, seven pairs. 8. Oenothera laciniata var. grandiflora, seven pairs. 9. Oenothera laciniata var. pubescens, a ring of fourteen. 10. Oenothera tetragona, a ring or six, a chain of six, four rings of four, one chain of four, and five pairs. 11. Oenothera coronopifolia, a chain of eight, four rings of four, and two pairs. 12. Oenothera tubicula, seven pairs. 13. Oenothera greggii var. lampasana five pairs and a ring of four. All drawings X 1600. ' 519 ONAGRACEAE APRIL, 1960]

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4.

10.

13. 10~

PLATE 4 520 ALISO [VOL. 4, No.3 the large flowered variety grandiflora having seven pairs (it also has rings of intermediate size) and the small-flowered Oe. pubescens having a ring of fourteen. The two counts of the typical variety could not be analyzed exactly, but one had a large ring, probably of four­ teen chromosomes. Oenothera: Salpingia. A gametic number of seven for all of the collections in the three species reported here indicates that this may be a strictly diploid subgenus. Rings of both small and intermediate sizes occur, but large rings have not been found.

SUMMARY AND CONCLUSIONS A study of the meiotic chromosomes of six genera, Gaura, Jussiaea, Ludwigia, Lopezia, Oenothera and Stenosiphon, of the Onagraceae is reported here. The findings of this study and similar studies in these or closely related genera allow some interesting comparisons and point out areas in which additional work is needed. The basic chromosome number was found to be the same for all of the species of each genus, but differed between some of the genera. Three basic numbers were found in the genera reported here. Gaura, Oenothera and Stenosiphon are all based upon the number seven and appear to be quite closely related to each other. Jussiaea and Ludwigia have a basic number of eight and have been suggested by other authors (Brenan, 1953; Hara, 195 3) to be congeneric, a suggestion to which the evidence presented here lends support. It now appears that Lopezia has a basic number of 10. Observations have been made of supernumerary chromosomes in four tetraploid plants of Gaura coccinca. These were found to resemble most closely those reported by Cleland (1951). Polyploidy has been found in four of the six genera reported here and appears to be an important factor in the evolution of most genera in the family. Lopezia and Stenosiphon are the only genera reported here which did not have polyploid species. The highest level of polyploidy was a dodecaploid, Jussiaea peruviana. Polyploidy in Oenothera appears to be most advanced in the subgenus Kneiffia in which there are two species with no known diploid representatives and one of these is reported (Hecht, 1942) to have an octoploid level. Hexaploids were found in Gaura, Ludwigia and Oenothera. Tetraploids are known in all four of the genera reported here to be polyploids. It appears that polyploid species in the family may have originated in two ways. In the polyploid species of Oenothera, subgenera Hartmannia, Kneiffia, Anogra and Raimannia, and also in the genus Gaura, the meiotic configurations strongly suggest them to be of auto­ ploid origin (Lewis et al., 1958; Snow, 1959). This was strengthened further by the work of Hecht (1942) when he treated a diploid Oe. rhombipetala having a ring of four and five pairs with colchicine and obtained tetraploids with an association of eight chromosomes, some quadrivalents and a few bivalents. Such multivalent associations were common in all of the polyploid species which were examined here and by other workers who have reported observations in the above mentioned groups. In some of the higher polyploid levels, how­ ever, such as in Oe. speciosa var. childsii (Hagen, 1950) and in Oe. fruticosa and in Gaura coccinea the pattern may be complicated further by some hybridization resulting in an auto­ allopolyploid. In all of these, however, there is a high degree of multivalent association. The polyploid species of Oenothera, subgenera Spaerostigma and Eulobus, have been found (Lewis et al., 1958) to have meiotic configurations composed of bivalents such as would be expected if they had originated through hybridization and were therefore allo­ polyploids. Polyploid species which exhibit the allopolyploid pairing are more common in the family and scattered through several genera including: Gayophytum, Epilobium, Bois­ duvalia, Clarkia, and Jussiaea (Lewis et al., 1958). It has been suggested by Dr. Munz (oral comm.) that the subgenera of Oeonthera which exhibit the autoploid type of origin may be distinguished from those which are of the allo- APRIL, 1960] ONAGRACEAE 521 ploid type on morphological grounds. The autoploid subgenera have four-lobed stigmas and the others have stigmas of the sphaerical type. Polyploids have not yet been reported for the subgenera Calylophis and Salpingia which have stigmas of the discoid type. Additional morphological studies are now needed in the various polyploids in conjunction with geo­ graphical, ecological and chromosome studies in order to delimit the true biological species in these complexes.

LITERATURE CITED Beeks, R. M. 1955. Improvements in the squash technique for plant chromosomes. El Aliso 3: 131-133. Bhaduri, P. N. 1941. Cytological studies in the genus Gaur a. Ann. Bot., n. s. 5: 1-14. ---. 1942. Further cytogenetical investigations in the genus GaUI·a. Ann. Bot., n. s. 6: 229-244. Brenan,]. P. M. 1953. Notes on African Onagraceae and Trapaceae. Kew Bulletin No. 1: 163-172. Cleland, R. E. ( ed.) 1950. Studies in Oenothera cytogentics and phylogeny. Indiana Univ. Pub!., Science series No. 16, Bloomington. ---. 1951. Extra, diminutive chromosomes in Oenothera. Evolution 5: 165-176. Darlington, C. D. and A. P. Wylie. 1955. Chromosome atlas of flowering plants. George Allen and Unwin, Ltd., London. Hagen, C. W., Jr. 1950. A contribution to the cytogenetics of the genus Oenothera with special refer- ence to certain forms from South America, in Cleland, 1950, pp. 305-348. Hara, H. 1953. Ludwigia versus Jussiaea. Journal Japanese Botany 28: 289-294. Hecht, A. 1942. Colchicine-induced tetra ploidy in Oenothera. Proc. Indiana Acad. Sci. 51: 87-93. ---. 1950. Cytogenetic studies of Oenothera, subgenus Raimannia, in Cleland, 1950, pp. 255-304. Johansen, D. A. 1929. A proposed phylogeny of the Onagraceae based primarily on number of chromo- somes. Proc. Nat. Acad. Sci. 15: 882-885. Lewis, H. and M. Lewis. 1955. The genus Clarkia. Univ. Calif. Pub!. Bot. 20: 241-392. ---, P. H. Raven, C. S. Venkatesh, and H. L. Wedberg. 1958. Observations of meiotic chromosomes in the Onagraceae. Aliso 4: 73-86. Linder, R. and J. Brun. 1957. L'incompatibilite dans Oenothera serrulata Nutt. Experientia 13: 23-24. Munz, P. A. 1928. Studies in Onagraceae. II. Revision of the North American species of subgenus Sphaerostigma, genus Oenothera. Bot. Gaz. 85: 233-270. ---. 1929. Studies in Onagraceae. III. A revision of the subgenera T araxia and Eulobus of the genus Oenothera. Amer. Jour. Bot. 16: 246-257. ---. 1929. Studies in Onagraceae. IV. A revision of the subgenera Salpingia and Calylophis of the genus Oenothera. Amer. Jour. Bot. 16: 702-715. ---. 1930. Studies in Onagraceae. V. The North American species of the subgenera Lavauxia and Megapterium of the genus Oenothera. Amer. Jour. Bot. 17: 358-370. ---. 1931. Studies in Onagraceae. VI. The subgenus Anogra of the genus Oenothera. Amer. Jour. Bot. 18: 309-327. ---. 1931. Studies in Onagraceae. VII. The subgenus Pachylophis of the genus Oenothera. Amer. Jour. Bot. 18: 728-738. ---. 1932. Studies in Onagraceae. VIII. The subgenera Hartmannia and Gauropsis of the genus Oenothera. The genus Gayophytum. Amer. Jour. Bot. 19: 755-778. ---. 1935. Studies in Onagraceae. IX. The subgenus Raimannia. Amer. Jour. Bot. 22: 645-663. ---. 1937. Studies in Onagraceae. X. The subgenus Kneiffia (genus Oenothera) and miscellaneous new species of Oenothera. Bull. Torrey Bot. Club 64: 287-306. ---. 1938. Studies in Onagraceae. XI. A revision of the genus GaUl· a. Bull. Torrey Bot. Club 65: 105-122, 211-228. ---. 1944. Studies in Onagraceae. XIII. The American species of Ludwigia. Bull. Torrey Bot. Club 71: 152-165. ---. 1947. In Hoehne, F. C. Flora Brasilica 41 ( 1): Fasc. 9: 1-62. Snow, R. 1959. Chromosome numbers of California plants, with notes on some cases of cytological in­ terest. Madrofio 15: 81-89. Tackholm, G. 1914. Zur Kenntnis der Embryosackentwicklung von Lopezia coronata Andr. Svensk. Bot. Tidskr. 8: 223-234.